Base materials

For wetted parts, stainless steel SS316 is the most common material. Depending on the aggressivity of the mixed media, 904, duplex stainless steel or titanium are often applied. The surface roughness of wetted parts varies from cold/hot rolled steel, pickling, sand or glass blasting up to Ra0.2 to 0.8 grinded or polished depending of cleanability requirements. Normally, carbon steel and cast iron are applied for non-wetted parts, but in special conditions stainless steel can be applied.

Linings

For the most aggressive conditions, wetted parts are protected against corrosion or wear by a rubber or other polymer lining.

Materials are selected based on corrosion and abrasion conditions inside the tank. Mechanical properties in relation to the required agitation forces also play a role when selecting materials. Ideally, solid materials are applied, but sometimes linings have to be used due to the availability, cost or a poor combination of wear and mechanical strength of the base material.